【单选题】3 / 8已知HA=50.000 mH_A=50.000\,\mathrm{m}HA=50.000m,a=1.234 ma=1.234\,\mathrm{m}a=1.234m,b=1.456 mb=1.456\,\mathrm{m}b=1.456m,则HBH_BHB为?A49.778 m49.778\,\mathrm{m}49.778m正确B50.222 m50.222\,\mathrm{m}50.222mC51.234 m51.234\,\mathrm{m}51.234mD48.544 m48.544\,\mathrm{m}48.544m参考答案A参考解析HB=50.000+(1.234−1.456)=49.778 mH_B=50.000+(1.234-1.456)=49.778\,\mathrm{m}HB=50.000+(1.234−1.456)=49.778m。